[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 220554
SWODY2
SPC AC 220553

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1253 AM CDT FRI APR 22 2005

VALID 231200Z - 241200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 35 SSE
CEW MAI 55 ESE MCN CAE LYH IPT AVP 35 ENE ABE ACY ...CONT... MLB
SRQ.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 WNW ART GFL ORH
BID ...CONT... PNS DHN SPA HKY BLF HTS LUK 30 SE FWA 40 SE DTW.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 55 N FCA CTB BIL SHR
DGW 50 NW AKO LIC LHX TAD ALS ASE CAG LND JAC SUN BNO 4LW 55 NE SVE
WMC EKO U24 ELP.

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS MID-ATLANTIC REGION TO
NRN/CENTRAL FL...

...SYNOPSIS...
SYNOPTIC UPPER AIR PATTERN WILL BE CHARACTERIZED BY LARGE UPPER
LEVEL CYCLONE OVER GREAT LAKES STATES...ANCHORING MEAN ERN CONUS
TROUGH.  CYCLONE IS FCST TO EVOLVE FROM MID/UPPER LEVEL LOW NOW OVER
 NEB...AND POSITIVELY TILTED SHORTWAVE TROUGH NOW DIGGING SEWD
ACROSS NWRN ONT...SERN MANITOBA AND NERN ND.  LATTER TROUGH SHOULD
PIVOT SEWD THEN EWD AROUND PRIMARY VORTEX CENTER OVER NEXT TWO DAYS.
 THOUGH DIFFERING IN DETAILS OF LARGER SCALE VORTEX SHAPE AND CENTER
POINT...21Z SREF MEMBERS ARE IN VERY GOOD AGREEMENT WITH ONE ANOTHER
AND WITH 00Z OPERATIONAL ETA/NGM/SPECTRAL RUNS REGARDING THIS TROUGH
BEING LOCATED INVOF SRN APPALACHIANS BY 18Z.

MEANWHILE HIGH AMPLITUDE RIDGE WILL EXTEND FROM W-CENTRAL
MEX NWD ACROSS CENTRAL/NRN ROCKIES TO CANADIAN HIGH PLAINS. 
UPSTREAM...ANOTHER LARGE MID/UPPER LEVEL CYCLONE -- NOW EVIDENT IN
MOISTURE CHANNEL IMAGERY W OF CA BETWEEN 130W-140W -- IS EXPECTED TO
MOVE SLOWLY EWD THROUGH DAY-2. BROAD PACIFIC CYCLONE IS FCST TO
FORCE SEAWARD RETROGRESSION OF SMALLER UPPER LOW NOW ANALYZED OVER
ORE.  SHORTWAVE TROUGH -- NOW ORBITING BACKSIDE OF THAT CIRCULATION
NEAR 31N138W -- SHOULD PIVOT AROUND SRN SEMICIRCLE OF PACIFIC
VORTEX...MOVING NEWD ACROSS COASTAL CENTRAL/SRN CA NEAR MIDDLE OF
PERIOD.

...MID ATLANTIC AREA SWD...
EARLY IN PERIOD...SCATTERED-NUMEROUS TSTMS EXPECTED FROM CENTRAL/ERN
PA AND WRN NY SWD AT LEAST THROUGH CAROLINAS...PERHAPS LINKED WITH
CONVECTION OVER NERN GULF AND COASTAL FL PANHANDLE REGION.  EXPECT
BUOYANCY TO DIMINISH WITH NWD EXTENT FROM TIDEWATER AND VA
PIEDMONT...WHILE DEEP-LAYER SHEAR AND FRONTAL/PREFRONTAL CONVERGENCE
SHOULD WEAKEN WITH SWD EXTENT OVER SERN STATES.

GREATEST SEVERE PROBABILITIES WITHIN BROADER CATEGORICAL SLGT ARE
DRAWN FROM INLAND MID ATLANTIC SWD OVER PIEDMONT AND COASTAL PLAIN
OF CAROLINAS.  PRIND THIS AREA IS WHERE STRONG DEEP-LAYER WIND
FIELDS...ACCOMPANYING SPEED SHEARS AND LATE MORNING TO MID-AFTERNOON
MUCAPE MAY BE BEST JUXTAPOSED. EXPECT STRONG LOW-MIDLEVEL SHEAR
OVER SERN SEMICIRCLE OF GREAT LAKES CYCLONE TO OVERSPREAD DIURNALLY
HEATED AND DESTABILIZING BOUNDARY LAYER...WITH ENOUGH MOISTURE TO
SUPPORT TSTMS. PRIND CONVECTION WILL DEVELOP INVOF PREFRONTAL LEE
TROUGH AND CONFLUENCE AXIS EARLY IN PERIOD...WITH RESULTING TSTMS
MOVING EWD ACROSS REGION.  AS MID/UPPER TROUGH APCHS...FLOW ALOFT
SHOULD BACK WITH TIME...CONTRIBUTING TO NEARLY UNIDIRECTIONAL
DEEP-LAYER PROFILES.  THIS COMBINED WITH LIKELIHOOD OF LINEAR
FORCING INDICATES DAMAGING WIND IS MAIN THREAT.  SUPERCELLS AHEAD OF
OR EMBEDDED WITHIN MAIN CONVECTIVE PLUME ALSO ARE POSSIBLE.

...WRN ORE...
WIDELY SCATTERED TSTMS MAY DEVELOP OVER CASCADE REGION WITH
AFTERNOON HEATING OF HIGHER TERRAIN.  A FEW MAY PRODUCE HAIL/GUSTS
NEAR SEVERE LEVELS.

SFC OBS INDICATE DEW POINTS RELATIVELY MAXIMIZED IN 40S TO LOW 50S
OVER THIS AREA...PROGGED TO REMAIN THROUGH SATURDAY AFTERNOON. COLD
MIDLEVEL AIR ASSOCIATED WITH PERTURBATION ALOFT WILL MAINTAIN STEEP
MIDLEVEL LAPSE RATES...CONTRIBUTING TO ENOUGH MLCAPE TO SUPPORT
THUNDER.  ETA/SPECTRAL PLANAR PROGS AND FCST SOUNDINGS INDICATE SELY
MID/UPPER LEVEL FLOW AROUND RETROGRADING LOW AND ELY TO NELY/UPSLOPE
FLOW IN BOUNDARY LAYER.  THIS CONTRIBUTES TO POSITIVE LOW LEVEL SRH
FOR SLOW MOVING STORMS...A RESULT OF VEERING WITH HEIGHT AND
SUFFICIENTLY WWD-SKEWED 0-3 KM HODOGRAPH.  MIDLEVEL FLOW IS PROGGED
TO BE ONLY 10-20 KT OVER REGION.  STILL...ENOUGH LOW LEVEL SHEAR AND
BUOYANCY ARE PROGGED TO CONSIDER MARGINAL AND SUBCATEGORICAL SEVERE
PROBABILITIES.

..EDWARDS.. 04/22/2005

...NOTICE...
THE STATION RELATIVE POINTS IN THIS PRODUCT ARE NOW AVAILABLE
SEPARATELY UNDER THE WMO HEADINGS WUUS01 PTSDY1...
WUUS02 PTSDY2...WUUS03 PTSDY3.  THE INCLUSION OF POINTS
IN THIS DISCUSSION WILL BE DISCONTINUED AFTER THE 2005
CONVECTIVE SEASON.  A PUBLIC NOTIFICATION STATEMENT (PNS)
WILL PROVIDE DETAILS ON THE TRANSITION.